Collaborative Research: Evaluation of Cumulus Petrofabrics Using Magnetic Fabrics

合作研究：使用磁性织物评估积云石油织物

• 批准号: 9902895
• 负责人: Jeffrey Gee
• 金额: $ 12.85万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9902895&HistoricalAwards=false
• 关键词: Collaborative; Research; Evaluation; Cumulus; Petrofabrics

9902895GeeThe fabrics of cumulus rocks preserve the only direct evidence of the mechanical processes involved in fractional crystallization of silicate liquids. Quantification of these igneous fabrics and understanding their origin is critical since the mechanical processes that give rise to the fabrics have chemical as well as textural consequences. Because quantitative petrographic studies of fabrics are time consuming, we propose to use cumulates from the Stillwater complex, Montana to develop an approach for relating magnetic fabrics (that are sensitive to both the orientation of magnetic minerals as well as the silicate minerals) to silicate fabrics in ultramafic and mafic cumulates. These magnetic methods have the advantage of providing direct 3D fabric information, having precision to detect small degrees (~0.5%) anisotropy, and being rapid enough to collect fabric data from a large number of samples. Our initial results suggest that these magnetic techniques provide accurate information on magmatic foliations and, in some cases, recover lineations that are not evident from petrographic analysis alone. If igneous fabrics can be analyzed and quantified in the systematic manner that geochemical data are collected, then studies of cumulates will progress past the point of speculating as to the importance of mechanical processes to documenting their importance.

9902895 Gee积云岩石的组构保留了硅酸盐液体分离结晶过程中所涉及的机械过程的唯一直接证据。这些火成组构的量化和了解其起源是至关重要的，因为产生组构的机械过程具有化学和结构后果。由于定量岩相研究的织物是耗时的，我们建议使用累积从斯蒂尔沃特复杂，蒙大拿州开发一种方法有关的磁性织物（这是敏感的磁性矿物的方向以及硅酸盐矿物）的硅酸盐织物在超镁铁和镁铁累积。这些磁性方法具有提供直接3D组构信息的优点，具有检测小程度（~0.5%）各向异性的精度，并且足够快速以从大量样品收集组构数据。我们的初步结果表明，这些磁技术提供了准确的信息，岩浆叶理，并在某些情况下，恢复线理是不明显的，从岩相分析。如果火成岩组构能够以收集地球化学数据的系统方式进行分析和量化，那么累积物的研究将超越推测机械过程的重要性的观点，以记录其重要性。